docs: def map_segments(func, neurites, neurite_type):
      ''' Map `func` to all the segments in a collection of neurites
  
          `func` accepts a section and returns list of values corresponding to each segment.
      '''
      neurite_filter = is_type(neurite_type)
      return [
          s for ss in iter_sections(neurites, neurite_filter=neurite_filter) for s in func(ss)
      ]